Yeah they completely redid the UI for the newer smart TVs. Only a few of the super high end models can be upgraded and even then it requires a special box that attaches to the back of the TV which costs ~$300. Why it requires a hardware upgrade just for a new UI is beyond me. They still use AdobeAir just like they always have.

Whatever I'm happy with the software running on my smart TVs and the apps they provide. (have a 60" in living room and 32" in office)

Boxee is a lowcost hardware media player. I believe it just has a subset of xbmc features, lacking DVR abilities.

Because I have TiVo to record TV, I use PLEX (Client-server application based on XBMC), which supports full 1080p playback on various devices such Roku2, iPad\iPhone, Andriod tablet\phone from a computer running PLEX server application. I have the Roku2 PLEX client which plays ripped my DVD\Bluray collection and I also use it to playback archive TV shows recorded from Tivo (after processing using VideoRedo).

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Two Series 3 TiVos, One TiVo Premiere, all with lifetime subs.
One dedicated media server with Steambaby and other media services.
Use VideoRedo for editing TiVo files.
Tivo user since 1999.

Ya but the hardware was not free and from what I can tell will also become useless (at least as an OTA DVR).

Only a few cities could even use the DVR service so if someone had the BoxeeTV and were not in one of those select cities, the DVR features never worked. I was in one of those areas and was able to use the DVR service. Fortunately though, I did not pay anything for my BoxeeTV. I would be pissed if I had payed for it.